A system of this type is known from European Patent No. 0188161. In this system, the two swivel joint devices for the passage of the cryogenic liquid and the return of the gas are independent devices, the conduit intended for the passage of the return of the gas concentrically surrounding the fixed conduit portion of the joint device for passage of the cryogenic liquid, with a layer of thermal insulation interposed between the two concentric conduits.
This system in swivel joint form has the disadvantage of having a complex structure and of being encumbering.